Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/58—Epoxy resins
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
  • C09J175/04—Polyurethanes
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/0053—Intermediate layers for image-receiving members
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2327/00—Polyvinylhalogenides
  • B32B2327/06—PVC, i.e. polyvinylchloride
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2363/00—Epoxy resins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2367/00—Polyesters, e.g. PET, i.e. polyethylene terephthalate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2375/00—Polyureas; Polyurethanes

Definitions

• This invention relates to adhesives for use in multilayer laminates in which at least one of the layers includes an ink-bearing surface.
• the invention features an adhesive composition that includes the reaction product of: (a) a polyester-based polyurethane; (b) an epoxy resin; (c) an epoxy-functional silane; and (d) an isocyanate-functional compound.
• the adhesive compositions are useful for preparing multilayer laminates in which a major surface of a first polymeric substrate is bonded to a major surface of a second polymeric substrate through the adhesive composition. One or both of those major surfaces includes an ink-bearing image.
• the adhesive compositions exhibit good adhesion (as measured by the 180 degree peel strength) to both ink-bearing polymeric substrates and non-ink bearing polymeric substrates.
• the compositions are particularly useful where the ink is an electrophotographic ink.
• suitable electrophotographic inks include polymers having a Tg no greater than about 30° C., while in other embodiments the ink includes a polymer having a Tg greater than about 30° C.
• a suitable ink is derived from gel organosol-containing, liquid toner compositions described, e.g., in Baker et al., U.S. Pat. No. 5,652,282 and Baker et al., U.S. Pat. No. 5,698,616, each of which is hereby incorporated by reference.
• toners include (a) a carrier liquid (e.g., an aliphatic hydrocarbon carrier liquid having a Kauri-Butanol number less than 30) and (b) a (co)polymeric steric stabilizer having a molecular weight greater than or equal to 50,000 Daltons and a polydispersity less than 15 covalently bonded to a thermoplastic (co)polymeric core that is insoluble in the carrier liquid.
• the core preferably has a Tg no greater than about 30° C.
• the toner may further include a colorant and a charge director.
• non-gel organosol-containing liquid toner compositions described, for example, in Baker et al., U.S. Pat. No. 5,886,067, hereby incorporated by reference.
• a suitable ink is derived from liquid toners described in Landa et al., U.S. Pat. No. 4,794,651; Landa et al., U.S. Pat. No. 4,842,974; Landa et al., U.S. Pat. No. 5,047,306; Landa et al., U.S. Pat. No. 5,047,307; Landa et al., U.S. Pat. No. 5,192,638; Landa et al., U.S. Pat. No. 5,208,130; Landa et al., U.S. Pat. No. 5,225,306; Landa et al., U.S. Pat. No.
• compositions are also useful with inks such as ink jet inks and lithographic inks. Any of these inks may be used alone or in combination with each other.
• the ink-bearing surface may include electrophotographically printed areas featuring an electrophotographic ink and offset printed areas featuring a lithographic ink.
• all the printed areas of the laminate are electrophotographically printed areas featuring an electrophotographic ink.
• the adhesive compositions exhibit good adhesion to a number of polymeric substrates.
• the adhesive is used to bond a rigid core layer to a flexible overlay film, where at least one of these materials includes an ink-bearing surface.
• at least one of the substrates is substantially transparent to permit viewing of the printed image on the ink-bearing surface.
• suitable polymeric substrates are selected from the group consisting of polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, polyesters, polyolefins, polycarbonates, and combinations thereof. Also suitable are microporous substrates such as TeslinTM films commercially available from PPG, Inc. of Pittsburgh, Pa.
• One preferred construction includes a polyvinyl chloride substrate adhesively bonded to a substantially transparent polyester overlay film.
• the adhesive compositions are also useful for preparing laminated articles having more than two substrates.
• the article may include a core substrate having a pair of opposed major surfaces, each of which is bonded to a separate overlay film.
• Such constructions are particularly useful for articles having printed images on two different surfaces.
• the invention features a lamination process for preparing the above-described articles.
• the ink-bearing image preferably is performed according to an electrophotographic imaging process that includes:
• the toner preferably is a liquid toner.
• Preferred liquid toners include a film-forming polymer.
• the film-forming polymer has a Tg no greater than about 30° C., while in other embodiments the film-forming polymer has a Tg greater than about 30° C.
• the article may subjected to a number of operations, including slitting, cutting, hole punching and drilling, foil stamping, sewing and grommeting, foil stamping, perforation, folding, surface texturing, and the like.
• the black, positive-acting, film-forming, electrophotographic ink used in the examples was prepared at an organosol/pigment ratio of 6 following the procedure described in Example 40 of U.S. Pat. No. 5,652,282 modified as follows.
• the gel organosol prepared according to the procedure of Example 22 of U.S. Pat. No. 5,652,282 was mixed using a Silverson mixer (Model L2R, Silverson Machines, Ltd.) operated at the lowest speed setting. After mixing for five minutes, 1912 g of the homogenized organosol at 16.14% (w/w) solids in NORPAR 12 were combined with 1031 g of NORPAR 12 (Exxon Chemical Co., Houston, Tex.), 51 g of MONARCH 120 carbon black (Cabot Corp., Billerica, Mass.), and 6.08 g of Zirconium HEX-CEM (OMG Chemical Company, Cleveland, Ohio) in a 4.0 liter polyethylene container.
• a Silverson mixer Model L2R, Silverson Machines, Ltd.
• This mixture was then milled in ten vertical bead mills, each having a capacity of 0.5 liter (Model 6TSG-1/4, Aimex Co. Ltd., Tokyo, Japan) by placing 300 g of millbase and 390 g of 1.3 mm diameter Potters glass beads (Potters Industries, Inc., Parsippany, N.J.) in each mill. Each mill was operated at 2,000 rpm for 1.5 hours without cooling water circulating through the cooling jacket of the milling chamber.
• This 3% toner was tested on the toner plating apparatus described in U.S. Pat. No. 5,652,282.
• the reflection optical density (ROD) was greater than 1.47 at plating voltages greater than 400 volts.
• An adhesive coating solution was prepared by adding methyl ethyl ketone (201 g), Epon 1007F epoxy resin (143 g of a 20 wt. % solution in methyl ethyl ketone, available from Shell Chemical Co.), epoxycyclohexylethyl trimethoxy silane (14.4 g, available from Aldrich Chemical Co.), and Vestanat T1890E isocyanate (215 g of a 20 wt. % solution in methyl ethyl ketone, available from Creanova) to 1428 g of a solution of Desmocoll 8634 polyurethane resin (15 wt. % in methyl ethyl ketone, available from Bayer Chemical Co.). The solution was applied to Mellinex 454 polyester film (0.92 mil, available from Dupont) at a wet coating coverage of approximately 375 g/square meter and dried to give an adhesive-coated film. The dry thickness of the adhesive layer was 1.0 mil.
• the adhesive portion of the film was area printed using a liquid toner-based, black, positive-acting, film-forming, electrophotographic ink (prepared as described above) to a net optical density of 1.6.
• the net optical density is equal to the white light optical density minus the white light optical density of unprinted film, measured in reflectance mode with a Macbeth densitometer.
• the net optical density corresponded to an ink net optical density of 1.3 for a paper substrate printed under identical conditions.
• the adhesive-coated film was laminated to a white polyvinyl chloride substrate.
• the article was cut into strips measuring one inch wide and the 180 degree peel force required to cause delamination was measured 15 minutes after the lamination step using an Instron Tester (Model 5542).
• the crosshead speed was 12 inches/minute.
• the peel force was determined to be 4.5 pounds/inch (7.9 N/cm).
• unprinted adhesive film was laminated to an identical white polyvinyl chloride substrate in an identical manner.
• the peel force was determined to be approximately 12 pounds/inch (21 N/cm), which resulted in tearing of the polyester film.
• a laminated article was prepared following the procedure of Example 1 except that lamination took place 30 minutes after printing.
• the peel strength was determined to be 1.9 pounds/inch (3.4 N/cm).
• the experiment was then repeated except that subsequent to the printing step, the printed polyester film was heated at 100° C. for 2 minutes and then laminated after a total of thirty minutes had elapsed since the printing step.
• the peel force measured approximately five minutes after the lamination, was 2.4 pounds/inch (4.2 N/cm).
• Example 1 The procedure of Example 1 was followed except that the adhesive was prepared by combining 15 parts Desmocoll 530, 85 parts methyl ethyl ketone, 3 parts Vestanat T1890E isocyanate, 1 part epoxycyclohexylethyl trimethoxy silane, and 2 parts Epon 1007F epoxy resin.
• the resulting article exhibited a peel force, measured as described in Example 1, of 4.0 pounds/inch (7.0 N/cm).
• the failure mode was ink splitting.

Abstract

Description

Claims (18)

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Cited By (16)

Citations (139)

• 1999
  • 1999-09-09 US US09/392,903 patent/US6221545B1/en not_active Expired - Fee Related

Patent Citations (142)

Non-Patent Citations (16)

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